Go Q & A


How are arrays different from slices in Go?

Arrays and slices are both fundamental data types in Go, but they have different characteristics and are used for different purposes.

An array in Go is a fixed-size sequence of elements of the same type. Once defined, the size of an array cannot be changed, and all elements must be of the same type. Arrays are declared using the following syntax:


var arrayName [size]dataType

Slices, on the other hand, are dynamic views into arrays. A slice is defined by specifying a contiguous section of an array, and it can grow or shrink dynamically as needed. Slices are declared using the following syntax:


var sliceName []dataType

The key differences between arrays and slices in Go include:


Fixed Size vs. Dynamic Size: Arrays have a fixed size determined at compile time, while slices are dynamically sized and can grow or shrink during runtime.

Pass by Value vs. Pass by Reference: Arrays are passed by value, meaning that a copy of the entire array is passed to functions. Slices, however, are passed by reference, allowing efficient sharing of underlying data between different parts of the program.

Flexibility: Slices provide more flexibility than arrays due to their dynamic nature. Slices can be resized, appended to, and sliced to create new slices efficiently.


Arrays are suitable for situations where a fixed-size sequence of elements is required, while slices are preferred for scenarios where dynamic resizing and flexibility are needed. Understanding the differences between arrays and slices is essential for writing idiomatic and efficient Go code.

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Over 5 years of experience in Golang. Led the design and implementation of a distributed system and platform for building conversational chatbots.